Current knowledge of the environmental influences on Australian cashmere production and quality

Goat fibre production is affected to a similar extent by genetic and environmental influences. Environmental influences include bio-geophysical factors (photoperiod, climate-herbage system and soil-plant trace nutrient composition), country of origin, nutrition factors (live weight, growth patterns) and management factors (farm, herd age and sex structure). Nutrition and management influences discussed include rate of stocking, energy nutrition, live weight change, parturition and management during shearing. The nutritional variation within and among years is the most important climatic factor influencing cashmere production, fibre diameter and fibre curvature (crimp). With productive cashmere goats, large responses to energy supplementation have been measured with optimum nutritional management. The effects and importance of management and hygiene during fibre harvesting (shearing) in producing quality fibre are emphasised.

Nutrition, management and other environmental influences on the quality and production of mohair and cashmere with particular reference to mediterranean and annual temperate climatic zones : a review

Goat fibre production is affected by genetic and environmental influences. Environmental influences which are the subject of this review include bio–geophysical factors (photoperiod, climate–herbage system and soil–plant trace nutrient composition), nutrition factors and management factors. Nutrition and management influences discussed include rate of stocking, supplementary feeding of energy and protein, liveweight change, parturition and management during shearing. While experimental data suggest affects of seasonal photoperiod on the growth of mohair and cashmere are large, these results may have confounded changes in temperature with photoperiod. The nutritional variation within and among years is the most important climatic factor influencing mohair and cashmere production and quality. Mohair quality and growth is affected significantly by rate of stocking and during periods of liveweight loss by supplementary feeding of either energy or protein. Strategic use of supplements, methods for rapid introduction of cereal grains, influence of dietary roughage on intake and the economics of supplementary feeding are discussed. Cashmere production of young, low producing goats does not appear to be affected by energy supplementation, but large responses to energy supplementation have been measured in more productive cashmere goat strains. The designs of these cashmere nutrition experiments are reviewed. Evidence for the hypothesis that energy-deprived cashmere goats divert nutrients preferentially to cashmere growth is reviewed. The influence and potential use of liveweight manipulation in affecting mohair and cashmere production and quality are described. Estimates of the energy requirements for the maintenance of fibre goats and the effect of pregnancy and lactation on mohair and cashmere growth are summarised. The effects and importance of management and hygiene during fibre harvesting (shearing) in producing quality fibre is emphasised. The review concludes that it is important to assess the results of scientific experiments for the total environmental content within which they were conducted. The review supports the view that scientific experiments should use control treatments appropriate to the environment under study as well as having controls relevant for other environments. In mediterranean and annual temperate environments, appropriate controls are liveweight loss and liveweight maintenance treatments. Mohair producers must graze goats at moderate rates of stocking to maximise animal welfare, but in so doing, they will produce heavier goats and coarser mohair. In mediterranean and annual temperate environments, seasonal changes in liveweight are large and influence both quality and production of mohair and cashmere. Mohair and cashmere producers can manipulate liveweight by supplementary feeding energy during dry seasons to minimise liveweight loss, but the economics of such feeding needs to be carefully examined. Strategic benefits can be obtained by enhancing the growth of young does prior to mating and for higher producing cashmere goats.

Frequency of shearing increases growth of fibre and changes objective and subjective attributes of Angora goat fleeces

The impact of genotype and of frequency and timing of shearing, on mohair attributes and production of modern Angora goats was studied. Goats in the southern hemisphere grazed pastures between February 2004 and 2006. There were seven shearing treatments by three genetic strains with four or eight replicates of individual goats. Treatments were: three different 6-month shearing intervals and two of 12-month shearing intervals with different months of shearing, a 7-month winter shearing interval and a 3-month shearing interval. Genetic strain was based on sire line: 1·0 South African; 1·0 Texan; and Mixed 0·5 South African and 0·5 Texan. Annual greasy mohair production was 5·08 kg, and average clean fleece production was 4·37 kg. The Angora goats produced an annual clean fleece equivalent to 0·122 of their mean fleece-free live weight which was equal to 0·34 g/kg/day. Measurements were analysed over the period of spring 2004 shearing to spring 2005 shearing, excluding the June–December shearing treatment. Increased frequency of shearing increased fleece growth and affected 13 objective and subjective attributes of mohair that were evaluated including clean washing yield, fibre diameter and fibre diameter variation, incidence of medullated fibres, staple length, fibre curvature, crimp frequency, style, staple definition, staple fibre entanglement and staple tip shape. The direction of these effects were generally favourable and for most attributes the magnitude of the response was linear and commercially important. Each additional shearing resulted in an additional 149 g of clean mohair representing 0·034 of the annual clean mohair production. This increase was associated with a 0·6 cm increase in staple length and 0·32 μm increase in mean fibre diameter. In conclusion, Angora goats shorn less frequently grew less mohair that was more likely to be entangled in spring. Managers of Angora goats should take note of these findings.

Lipid composition of cashmere goat fibres

This study examined the differences in the chemical composition, particularly fatty acids, of the lipid extracted from the fibre of bucks, does and castrated goats. The study provides a more detailed understanding of the chemical composition of buck fibre lipid and how it varies throughout the year, and also details the effect of body region and nutrition on the production and chemical composition of lipid from buck fibre. Lipid was extracted with either petroleum ether (non-polar) or chloroform/methanol azeotrope (polar) and analysed by gas chromatography and gas chromatography-mass spectrometry. The more polar solvent system extracted larger amounts of lipid and more of each individual fatty acid. The following buck specific ethyl branched fatty acids were identified: 2-ethylhexanoic, 4-ethylhexanoic, 2-ethyloctanoic, 4-ethyloctanoic, 6-ethyloctanoic, 2-ethyldecanoic, 4-ethyldecanoic, 2-ethyldodecanoic, 6-ethyldodecanoic, 4-ethyldodecanoic, 2-ethyltetradecanoic, 6-ethyltetradecanoic, 4-ethyltetradecanoic, 2-ethylhexadecanoic and 4-ethyloctadecanoic acids. Of these buck specific fatty acids only 4-ethylhexanoic (T), 4-ethyloctanoic, 4-ethyldecanoic, 4-ethyldodecanoic, 6-ethyldodecanoic (T), 4-ethyltetradecanoic, 2-ethylhexadecanoic (T) and 4-ethylhexadecanoic acids have been previously identified or tentatively identified (T) in buck fibre extracts. This shows that the chemical composition of buck fibre lipid is more complex than previously reported, and that it may be more difficult than previously thought to artificially duplicate the odour of the buck. Buck fibre samples had lower average concentrations of 2-methylpropanoic, 2-methylbutanoic, iso-pentadecanoic, anteiso-pentadecanoic, iso-hexadecanoic, anteiso-heptadecanoic, iso-octadecanoic and anteiso-nonadecanoic acids as compared with fibre samples from does, spayed does, or wethers that were castrated at one month of age. The reduced concentrations of these fatty acids in buck fibre extracts were likely to be due to the synthesis of ethyl branched derivatives of iso and anteiso fatty acids. Buck fibre samples had higher concentrations of benzoic acid as compared with fibre samples from does, spayed does, or wethers that were castrated at one month of age. The significance of these results is that non buck specific fatty acids may also make a contribution to the odour of bucks. When fibre samples were collected at various times throughout the year, it was found that the bucks had increased amounts of lipid and ethyl branched fatty acids in fibre samples shorn from March to September, as compared with fibre samples shorn in November and January. The increase in the amount of lipid and ethyl branched fatty acids corresponded with both the rutting period of the buck and the period when the buck odour was increased. This suggests that ethyl branched fatty acids could be pheromones. The variation in lipid content and fatty acid composition was also examined between fibre samples collected from different body regions of the buck during April, as alterations in sebaceous gland activity around the neck during rutting have been reported. It was found that the average amount of lipid in the neck region of the bucks was not statistically higher than the average amounts in the midside and hind regions. However, the ethyl branched fatty acid concentrations were statistically higher in the fibre from around the neck as compared with the fibre from the other body regions, which is consistent with the odour of the buck being most pronounced around the head and neck region. The lipid content and composition of fibre samples from bucks fed high and low quality diets (lucerne and pangola grass, respectively) was examined to determine the effect of nutrition on buck specific components. The high quality diet increased the amount of lipid and ethyl branched fatty acids in fibre samples collected in April from the neck, midside and hind regions, as compared with fibre samples from the corresponding body regions from bucks fed the low quality diet. Thus it may be possible for the pheromone levels of bucks to be increased by simply providing them with good nutrition. The lipid content and ethyl branched fatty acid concentrations of fibre samples increased earlier in the year for the lucerne fed bucks as compared with the pangola grass fed bucks. The lucerne fed bucks had increased concentrations of ethyl branched fatty acids in fibre samples shorn during December to June (6 months) whereas the pangola grass fed bucks had increased concentrations of ethyl branched fatty acids in fibre samples shorn during April to August (4 months). These observations show that good nutrition can result in both the earlier production of ethyl branched fatty acids and an extended period when ethyl branched fatty acids are produced. This suggests that nutrition can be used to manipulate pheromone levels in the buck. The period when the ethyl branched fatty acids were increased corresponded with the period when the plasma luteinizing hormone (LH) and testosterone concentrations, odour and sebaceous gland volume of the bucks were increased, which supports the assumption that ethyl branched fatty acids are involved in odour production and act as pheromones.

Cashmere production and fleece attributes associated with farm of origin, age and sex of goat in Australia

Differences in cashmere production and fleece attributes associated with farm of origin, age and sex were quantified for commercial Australian cashmere goat enterprises. From 11 farms in four states, 1147 does and 97 wethers were monitored, representing 1- to 13-year-old goats. Individual clean cashmere production ranged from 21 to 389 g, with a mean ± standard deviation value of 134 ± 62 g. The mean cashmere production of 2-year-old does from different farms varied from 69 to 225 g and averaged 141 g. Mean ± s.d. greasy fleece weight was 394 ± 123 g, clean washing yield was 90.8 ± 4.1%, clean cashmere yield 33.4 ± 9.4%, cashmere fibre diameter 16.4 ± 1.6 µm, fibre curvature 48 ± 8.7 degrees/mm and staple length 8.7 ± 2.1 cm. There were large, commercially significant differences between farms for clean cashmere weight, mean fibre diameter and other attributes of cashmere. These were much larger than the effects of age and sex. Farm and age accounted for 42 to 67% of the variation in clean cashmere production, mean fibre diameter, fibre curvature, staple length and clean washing yield. Farm of origin affected clean cashmere yield, accounting for 24% of the variation. Sex of the goats had only a minor effect on the staple length of cashmere. The responses to age of clean cashmere weight, mean fibre diameter and the inverse of fibre curvature are very similar. Generally, cashmere production and mean fibre diameter increased with age. For the majority of farms, cashmere fibre curvature declined in a curvilinear manner with increases in age of goat. There were large differences in cashmere staple length from different farms, with means ranging from 7 to 12 cm. Between 1 and 2 years of age, the staple length of cashmere demonstrated a constant proportional increase. At ages older than 2 years, staple length either declined or increased by less than 1 cm with age, depending on the farm of origin. This study demonstrates that there are large gains in productivity that can be achieved from Australian cashmere goats. A better understanding of on-farm factors that influence cashmere production would enable all producers to optimise their production systems.

The allometric relationship between mean fibre diameter of mohair and the fleece-free liveweight of Angora goats over their lifetime

As mean fibre diameter (MFD) is the primary determinant of mohair price we aimed to quantify the lifetime changes in mohair MFDas Angora goats aged and grew. Measurements were made over 12 shearing periods on a population of Angora goats representing the current range and diversity of genetic origins including South African, Texan and interbred admixtures of these and Australian sources. Records of sire, dam, birthweight, birth parity, liveweight, fleece growth and fleece quality were taken for does and castrated males (wethers) (n = 267 animals). Fleece-free liveweights (FFL_wt) were determined for each goat at shearing time by subtracting the greasy fleece weight from the liveweight recorded immediately before shearing. A restricted maximum likelihood growth curve model was developed for relating MFD to FFL_wt, age and other measurements.Asimple way of describing the results is:MFD= k (FFL_wt)b E; where k is a parameter that can vary in a systematic way with shearing(age), breed, weaning weight, sire, dam and individual; b is a parameter that is the same for nearly the whole study; and E are independent errors from a log-normal distribution. The analysis shows that ^b = 0.34, with s.e. (^b) = 0.021. Thus, mohair MFD was allometrically related to the cube root of FFLwt over the lifetime of Angora goats. However, the allometric proportionality constant differed in a systematic way with age at shearing, genetic strain, weaning weight, sire, dam and individual. For Texan-breed goats, MFD decreased as weaning weight increased (P = 0.00016). The findings indicate that management factors that affect liveweight and weaning weight have lifetime effects on mohair fibre diameter and therefore the value of mohair and the profitability of the mohair enterprise.

Sensory adaptability of foods with added Lupin (Lupinus angustifolius) kernel fibre using pre-set criteria

Fiber-enriched white bread, muffin. pasta, orange juice, and breakfast bar were prepared with lupin (Lupin us angusti/olius) kernel fiber. Consumer panelists (n = 44) determined that all these fiber-enriched foods, except orange juice, fulfilled pre-set acceptability criteria. Fiber enrichment did not change overall acceptability (p> 0.05) of the bread and pasta, but reduced overall acceptability (p < 0.05) of the muffin, orange juice, and breakfast bar. In all fiber-enriched products, flavor was the attribute most highly correlated with overall acceptability (p < 0.05). The lupin kernel fiber used in this study therefore appears to have potential as a 'nonintrusive' ingredient in some processed cereal-based foods_ For other applications, fiber modification appears worthy of investigation to accomplish 'nonintrusive' fiber enrichment.

Energy, protein, calcium, vitamin D and fibre intakes from meals in residential care establishments in Australia

Residents from high level (nursing homes) and low-level care facilities (hostel) being served the three common diet texture modifications (full diet, soft-minced diet and pureed diet) were assessed. Individual plate waste was estimated at three meals on one day. Fifty-six males and 156 females, mean age 82.9+/-9.5 (SD) years, of which 139 lived in nursing homes (NH) and 76 in hostels (H) were included. Mean total energy served from meals was 5.3 MJ/day, 5.1 to 5.6 MJ/day, 95% confidence intervals (CI), in NH which was less than in H, 5.9 MJ/day (CI 5.6 to 6.2 MJ/day) (P=0.007). Protein and calcium intakes were lower in NH, 44.5g (CI 41.5 to 47.5g), 359.0mg (CI 333.2 to 384.8mg), versus 50.5g (CI 46.6 to 54.3g), 480.5mg (CI 444.3 to 516.7mg) in H (P=0.017, P<0.001 respectively). There was no difference in nutrient/energy ratios, except for protein/energy, which was higher in NH 11.7 (CI 11.3 to 12.2) than in H 9.8 (CI 9.4 to 10.3) (P<0.001). Ability to self-feed had no significant effect on nutrient intakes in NH. The self fed group (N=63) had the following nutrient intakes: energy 4.0 MJ (CI 3.6 to 4.3 MJ), protein 44.6g (CI 40.3 to 48.9g), calcium 356.9mg (CI 316.3 to 397.4mg), fibre 14.9g (CI 13.2 to 16.5g). The assisted group (N=64) had the following nutrient intakes: energy 3.9MJ (CI 3.6 to 4.2MJ), protein 46.0g (CI 40.7 to 49.6), calcium 361.9mg (CI 327.8 to 396.1mg), fibre 14.9g (CI 13.2 to 16.1g). Of NH classified as eating impaired, 36% received no assistance with feeding and had lower intakes of protein 37.8g (CI 33.0 to 42.1g) compared to those receiving some assistance 46.1g (CI 41.3 to 50.9g) (P=0.026). Reduced energy intake accounted for the differences in nutrient intakes between nursing homes and hostels, except for protein. Strategies to effectively monitor nutrient intakes and to identify those with eating impairment are required in order to ensure adequate nutrition of residents in nursing homes and hostels.

The charge effect of cationic surfactants on the elimination of fibre beads in the electrospinning of polystyrene

Polystyrene nanofibres were electrospun with the inclusion of cationic surfactants, dodecyltrimethylammonium bromide (DTAB) or tetrabutylammonium chloride (TBAC), in the polymer solution. A small amount of cationic surfactant effectively stopped the formation of beaded fibres during the electrospinning. The cationic surfactants were also found to improve the solution conductivity, but had no effect on the viscosity. Only DTAB had an effect on the surface tension of the polymer solution, the surface tension decreasing slightly with an increase in the concentration of DTAB.

The formation of beaded fibres was attributed to an insufficient stretch of the filaments during the whipping of the jet, due to a low charge density. Adding the cationic surfactants improved the net charge density that enhanced the whipping instability. The jet was stretched under stronger charge repulsion and at a higher speed, resulting in an exhaustion of the bead structure. In addition, a polymer/surfactant interaction was found in the polystyrene–DTAB solution system, while this interaction was not found in the polystyrene–TBAC system. The polymer/surfactant interaction led to the formation of thinner fibres than those formed in the absence of the interaction.

The effects of a non-ionic surfactant, Triton X-405, on the electrospun fibres were also studied. The addition of Triton X-405 did not eliminate the fibre beads, but reduced the bead numbers and changed the morphology. Triton X-405 slightly improved the solution conductivity, and had a minor effect on the surface tension, but no effect on the viscosity.

Effect of fat replacement by insulin or lupin-kernal fibre on sausage patty acceptability, post-meal perceptions of satiety and food intake in men

The present study examined whether replacing fat with inulin or lupin-kernel fibre influenced palatability, perceptions of satiety, and food intake in thirty-three healthy men (mean age 52 years, BMI 27·4 kg/m²), using a within-subject design. On separate occasions, after fasting overnight, the participants consumed a breakfast consisting primarily of either a full-fat sausage patty (FFP) or a reduced-fat patty containing inulin (INP) or lupin-kernel fibre (LKP). Breakfast variants were alike in mass, protein and carbohydrate content; however the INP and LKP breakfasts were 36 and 37 % lower in fat and 15 and 17 % lower in energy density respectively compared with the FFP breakfast. The participants rated their satiety before breakfast then evaluated patty acceptability. Satiety was rated immediately after consuming the breakfast, then over the subsequent 4·5 h whilst fasting. Food consumed until the end of the following day was recorded. All patties were rated above ‘neither acceptable or unacceptable’, however the INP rated lower for general acceptability (P=0·039) and the LKP lower for flavour (P=0·023) than the FFP. The LKP breakfast rated more satiating than the INP (P=0·010) and FFP (P=0·016) breakfasts. Total fat intake was 18 g lower on the day of the INP (P=0·035) and 26 g lower on the day of the LKP breakfast (P=0·013) than the FFP breakfast day. Energy intake was lower (1521 kJ) only on the day of the INP breakfast (P=0·039). Both inulin and lupin-kernel fibre appear to have potential as fat replacers in meat products and for reducing fat and energy intake in men.

Lupin kernel fibre-enriched foods beneficially modify serum lipids in men

Objective: To examine the effect of a diet containing a novel legume food ingredient, Australian sweet lupin (Lupinus angustifolius) kernel fibre (LKFibre), compared to a control diet without the addition of LKFibre, on serum lipids in men.

Design: Randomized crossover dietary intervention study.

Setting: Melbourne, Australia — Free-living men.

Subjects: A total of 38 healthy males between the ages of 24 and 64 y completed the intervention.

Intervention: Subjects consumed an LKFibre and a control diet for 1 month each. Both diets had the same background menus with seven additional experimental foods that either contained LKFibre or did not. Depending on energy intake, the LKFibre diet was designed to contain an additional 17 to 30 g/day fibre beyond that of the control diet.

Results: Compared to the control diet, the LKFibre diet reduced total cholesterol (TC) (meanplusminuss.e.m.; 4.5plusminus1.7%; P=0.001), low-density lipoprotein cholesterol (LDL-C) (5.4plusminus2.2%; P=0.001), TC: high-density lipoprotein cholesterol (HDL-C) (3.0plusminus2.0%; P=0.006) and LDL-C:HDL-C (3.8plusminus2.6%; P=0.003). No effects on HDL-C, triacylglycerols, glucose or insulin were observed.

Conclusions: Addition of LKFibre to the diet provided favourable changes to some serum lipid measures in men, which, combined with its high palatability, suggest this novel ingredient may be useful in the dietary reduction of coronary heart disease risk.